If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

End Bars: parallel sides vs non-parallel sides

I've noticed that most, if not all, commercial wooden frames have End Bars that have their sides trimmed, so as to narrow them towards their bottom ends. I also noticed that Mann Lake, PF120 and PF125 plastic small-cell frames have, virtually no taper to their End Bars, and they are nearly parallel for their entire length.

I've only recently taken to designing and making my own wooden frames, and I've made all of mine, deep or medium, with parallel sided End Bars. Initially I made them with parallel sides, because I have almost always been suspect of frames made with the taper, and wanted to try a different design. I have learned to prefer these frames with parallel sided End Bars -- the primary benefit I see is that, what I call, "frame slap" is virtually eliminated. Frame slap is where the frames swing inside their supers, especially while being moved or while in transit, and slap against each other. This frame slap can be very harmful to the bees, and might even cause harm or even precipitate an untimely extirpation of the queen.

- - - - -
I began this thread, because I've seen several threads, recently, where attempts were being made, to create these narrowing End Bars. I am curious to know what, if anything, is perceived to be the benefit to this End Bar design.

Last edited by Joseph Clemens; 04-14-2014 at 08:29 AM.
Reason: slight adjustment of wording for clarity

Re: End Bars: parallel sides vs non-parallel sides

I've always thought that the narrow part was to allow the bees a shortened path to get around the end to the other side of the frame. With foundationless frames the bees normally leave themselves holes through the comb at various places around the edges, that I presumed were for getting to the other side. When I put plastic foundation in, I snap off the corners and the bees usually leave those corner holes open. I don't know if the bees agree with any of this, because frankly, it doesn't make much sense.

Re: End Bars: parallel sides vs non-parallel sides

Thanks for the feedback, so far. I appreciate it very much.

I, too, had thought that it was an attempt by us humans to make things easier for the bees. Similar to giving them a bottom entrance as wide as the entire hive, and with a small "porch"/alighting board (projection). But now that I've run many hives with narrowed End Bars and many with parallel End Bars, the only difference I see, is the increased stability of the frames in the hives - and the reduction of "frame slap" and its harmful effects. Plus fewer bees are injured between the edges of End Bars where they come together to space the frames. Without the differences in width of the End Bars, frames can be removed from the hive with less "rolling of bees", and less smashing of bees between End Bar edges. The parallel End Bar edges assist in keeping the comb faces spaced apart when a comb is being pulled out, and the End Bar edges don't have an angle that traps and smashes bees as the adjacent End Bars are slid back together when replacing a frame in the hive. Instead the bottom of the End Bar of the frame being reinserted simply pushes any bee(s) out of the way as that frame is being reinserted. Of course it is still possible to smash bees between the edges of adjacent End Bars, but a simple adjustment of technique can virtually eliminate bee injuries between adjacent End Bar edges.

If there are multiple frames removed, I insert frames with the End Bar edges against each other as I slide the next frame in, then, when there is only one frame still missing, I carefully push the frames that are already in the hive together or apart, so there is just a little more space than needed to insert the still missing frame into its space between the frames already there - it slides into its place without injury to a single bee, with the bottom edge of the End Bar of the frame being inserted, pushing any bees out of the way, without injury. And the parallel sides of the End Bar maintaining proper frame/comb spacing to nearly eliminate rolling during the pulling or replacement of frames.

I can't help but think that parallel End Bars might increase the life of queens in a beginner's hives. In retrospect, I can't help, but think that some of the sudden queenlessness I experienced in my hives, when I was newly into beekeeping, may have been due to those tapering End Bars, helping me to roll bees between combs, or slice/smash them between the edges of End Bars.

Last edited by Joseph Clemens; 04-14-2014 at 09:04 AM.
Reason: was slow to get into final version

Re: End Bars: parallel sides vs non-parallel sides

If desired, you can make a communication path by cutting the side of the end bar for a small distance(1 inch) about 2/3s down the bar from the top while leaving the bottom at the full width.

This allows the full width at the top to maintain its position while the gap slides past the opening in the bars beside it so the bottom of the bar does not hang-up as it passes the gaps beside it. Withdraw the frame slowly so bees do have time to clear the space as the feel the bottom of the bar slide by.

Re: End Bars: parallel sides vs non-parallel sides

jrbbees,

Yes, I like that idea. If I made a small dado cut, say 3/4" wide and 3/16" deep, on both sides of all End Bars, at the same place along their length (so they all match up). That would create a cross-over point, between combs, and still provide most of the observed benefits of parallel sided End Bars. I had thought of that, but am concerned that it will increase the chances of catching and harming bees as the frames are put back together. Of course, with proper technique, harm to bees between End Bar edges, can nearly be eliminated, no matter what End Bar design is used.

The one major drawback I would expect, is that every frame ever used would need to have the same dado cut/notch, or the damage to bees when putting the tweaked frames with untweaked frames could cause increased damage to bees, having a notch smaller than bee space on one frames End Bar and not the adjacent frame.

Re: End Bars: parallel sides vs non-parallel sides

Another idea, though I believe it has already been tried and found to be impractical, is to use very narrow End Bars, say 3/4" wide, and to space the frames in the supers using metal frame spacers. If they were matched in both the frame rest rabbet and the bottoms of each super, they would hold the frames in the desired spacing - always, but reduce other convenient options, like sliding frames across the hive on the frame rest rabbet's or adjusting the spacing for various reasons - like pushing a queen cage between Top Bars for introduction. There are spacers like this, in use, though I believe only some transport nucs use them in the bottom (to hold the bottoms of frames from moving). And they are usually used to properly space fewer frames, wider, for easier extraction during honey production.

Re: End Bars: parallel sides vs non-parallel sides

Bee-tech nailed it. Less length to propolize. Kelly even knife edges one side of the end bar to reduce the contact area between end bars. We prefer the top bars that are narrowed to a "teat" on the end, also to reduce propolizing. As to the frame slap, we are sedentary, and actually employ it to space the frames in a super before adding to a hive.

Re: End Bars: parallel sides vs non-parallel sides

Hoffman frames were design to reduce the contact area to make it easier to remove them. You should leave enough of the end bar full length to keep the frames properly spaces.

I've never had frames "slap" once the bees are using them, mine glue them down pretty well even with Hoffman design, to the point I have to pry them out. I tried full length end bars before I remembered I had a jointer to trim then down (you'd think tripping over it every day I worked in the shop would be a reminder, but no) and they are really difficult to remove, and worse to try to put back. Have to scrape the propolis off every single end bar, both sides, to get them back in.

That said, I don't move hives, so flopping frames isn't a problem for me. Boxes just go off the hive onto the cover next to it, never any further with bees on them excpet if I'm making a split or something. The frames don't move much.

Re: End Bars: parallel sides vs non-parallel sides

I don't generally have frame slap issues, except when someone is transporting a nuc away from my place. Earlier, many queens wouldn't make it safely to their destinations. I believe this is primarily due to the frame slap issue. I had to cage nuc queens for transport or they wouldn't make it home. That was tedious. Now, parallel sided End Bars help combs to always stay safely spaced apart (no frame slap), and nucs can now be transported without caging and without killing their queens.

Propolis hasn't ever been much of an issue. The bees collect it, but have never really used it generously. It's curious, but other beekeepers in my area do have propolis issues with some hives.